Infecções experimentais no coelho (Oryctolagus cuniculus L.) com nematodeos gastrintestinais de ovinos, bovinos e equinos

Abstract

The present study was carried out to evaluate the actuation of the rabbit (Oryctolagus cuniculus L.) as a host for experimental infections with gastrointestinal nematodes of sheep, cattle and horses, as well as the pathological lesions caused by these infections. Thirty rabbits of mixed breed were used, of various ages, 16 males and 14 females kept of the Experimental Station W. O. Neitz, of the Parasitology department, Biology Institute, of the Federal Rural University of Rio de Janeiro, Itaguaí, Rio de Janeiro State. Two rabbits were maintained as controls and 28 were inoculated; of these 9 were re-inoculated. In total, including all treatments, 907,000 infective larvae were used. During the experiment, the animals were sacrificed at different periods, when 21 were found to be positive (75%) and 7 were considered to be negative (25%). 62 The species of nematodes obtained in this experiment were Trichostrongylus colubriformis, T.axei and Cooperia punctata, with a total of 11,091 specimens as adults, corresponding to 1.223% of the infective larvae used, -3 as well as 60 inmatures, the equivalent of 6.0 x 10 % of the larvae used. Of the adult nematodes, 43.48% were males and 56.52% were females. Prepatent periods were between 12 to 21 days for T. colubriformis inoculated from sheep and 20 to 29 days for those inoculated from cattle: no eggs were produced by T. axei or c. punctata. No deaths or severe symptoms were seen as a result of the inoculations of infective larvae; variations in temperature and weight were slight. The macroscopic alterations seen were petechial haemorrhages in the small intestine and histopathological examination of this organ showed that alterations were most marked in those rabbits which had been re-inoculated. Principally, atrophy of the villi was seen in those animals inoculated with larvae from sheep and passaged in rabbits; cellular hyperplasia was seen in those animals inoculated with larvae from cattle and erosion of the villi in those rabbits inoculated with infective larvae obtained from horses.